Time-element device



Sept. 22, 1925.

E. FONS 7 TIME ELEMENT DEVICE Filed Nov. 22, 1920 Figl.

lnvehtorz 1 Eugene l oms,

H i s Attorney.

Patented Sept. 22, v

UNITED STATES 1,554,652 PATENT OFFICE.

EUGENE PONS, OF SGHENECTADY, NEW YORK, ASSIGNOR TO' GENERAL ELECTRIC COH- IPANY, A CORPORATION OF NEW YORK.

TIME-ELEMENT DEVICE.

Application filed November 22, 1920. Serial No. 425,712.

. and reliable time element device by the use of which a definite and predetermined time interval may be introduced in the operation of electric switches.

More specifically, my invention relates to a device which is set in operation in response to some predetermined condition or event and which after being set in operation will operate circuit controlling means associated therewith after a definite time interval. It is highly desirable that the time interval after being once set shall be unvarying in duration, that the device be simple and reliable and that means be pro vided for easily adjusting the length of the time interval to meet varying conditions of operation.

In carrying out my invention I obtain the desired time interval in a very simple and reliable manner by means of a rotatable element having axles of relatively small diameter adapted to roll on a support. The element is caused to roll by the application of .a force, for example, the force of gravity I if the support is held at an angle from the horizontal. This force must be constant and unvarying and the distance which the element rolls must be fixed for any setting of the device. Under the conditions as outlined above it will be obvious that the element will always consume an inherent and unvarying interval of time in reaching the end of its travel. By providing the element with axles of relatively small diameter the progressive movement of the element will be much slower than if the element rolled upon its 'own periphery. This is due to the inertia of the element which gives the retarding efi'ect characteristic of a flywheel.

My invention is capable of various applications in the control of electric circuits. It may be used to advantage as a protective device for circuits which are subject to momentary overloads which are not objectionable but sufl'icient to trip the ordinary circuit breaker. hen applied to a circuit of this character my device will be set in operation by the overload but will not open the circuit until after a definite time interval. If the load decreases to normal value before the expiration of this time interval the device will be reset to initial position without opening the circuit. In the starting of electric motors my invention may be used to delay for a suitable interval the successive closing of the starting switches. It is also particularly useful in the control of various types of industrial apparatus which are utilized for a short interval of time to perform a certain operation. An example of the latter is illustrated by a branding machine. When used in this connection my device may be set in operation simultaneously with the application of the branding iron, and after a desired time interval it will operate means to remove the branding iron.

For a better understanding of my invention reference is had to the accompanying drawings wherein Fig. 1 is a plan view of my improved time element device in circuitsection; Fig. 2 is a partial view of the device shown in Fig. 1 in open-circuit position; and Fig. 3 is a part sectional view of Fig. 1.

Referring to Figs. 1, 2 and'3, the time element device is suitably mounted on a base 10 of insulating material. A support or lever 11, which is pivotally supported between its ends by means of the strap 12 secured to the enclosing casing 18, is adapted to eifect the opening of switch contacts 14 and 15 which are included in any suitable manner in the electric circuit to be controlled. The lever 11 is made in the form of an inclined two rail track along which an element in the form of the flywheel 16 mounted on relatively small axles -22 is adapted to roll. The fulcrum of the lever is at a point such that the left hand end of the lever is longer than the right hand end. The right hand end of the lever is provided with weighted portions 17 and 18 which cooperate wlth the fly-wheel 16 to open the switch contacts 14 and 15 when the fly-wheel is to the right of the fulcrum of the lever on the support 12. The two tracks of the lever are joined at the left hand end of the lever to form the contact closed position with certain of the parts in 14 which extends through an opening 25 in the casing 13. Stationary contact 15 is in screw threaded engagement with a support 26 which is attached to the base 1O and is in position to be engaged by contact 14. Under normal conditions of operation the fly-wheel is held in the position shown in Fig. 1, the circuit-closing position, by means of a bell-crank lever 19 which is biased to the position shown by spring 23 and controlled by means of an electromagnet 20 having a movable plunger 21 pivotally secured to the short arm of the bell-crank. The long arm of the bell-crank lever engages the fiy-wheel and by reason of the effect of spring 23 and the weight of' the plunger 21 holds the fiy-wheel in the position at which the weight of the fiy-wheel maintains contact 14 in engagement with contact 15 and holds the lever at a definite angle with the horizontal.

As thus constructed and arranged, and with the parts in the positions as shown in Figs. 1 and 3, the operation of my invention is as follows :The winding of the electromagnet 20 will be energized to lift the plunger 21 in accordance with anypredetermined condition, such as in response to an excessive current flowing through the winding of the electromagnet, or in any case in which it is desired to openthe contacts 14 and 15 a predetermined interval of time after the winding of the electromagnet 20 is energized to lift the plunger 21. When the electromagnet 20 has been thus energized, the long arm of the bell-crank lever 19 will be moved against the tension of spring 23 fromengagement with the fiywheel to the position shown in Fig. 2. By reason of the fact that the lever 11 is inclined to an angle with the horizontal, the fly-wheel 16 will roll downward along the lever on its axles 22 which freely roll along the track of the lever. Due to its retarding effect it will take an appreciable time for thefly-wheel to -roll downward past the fulcrum of the lever and the contacts 14 and 15 will be maintained in engagement during this time.

The'weight of the flywheel with the cooperation of weights 17 and 18 will then tilt the left hand end of the lever upward and effect a quick opening of the contacts 14 and 15. A definite time interval is thus introduced in the opening of the electric circuit by the time taken by the fly-wheel in rolling along the track to the lower position. The lever, the flywheel, and the bell-crank lever will then be in'positions as shown in Fig. 2, the left hand end of the lever being held against the upper end of opening 25 and the bell crank lever serving to arrest the movement of the fly-wheel, and will remain in these positions, the contacts being held open, until the winding of the electromagnet 20 is shown in Fig. 1.

'deenergized. \Vhen this happens the bellcrank lever will be rocked about its pivot by reason of the dropping of the plunger 21 and the effect of spring 23, and the long arm of the bell-crank lever will push the fly-wheel from the position shown in F ig. 2 to its original position against stop 24 as The weight of the flywheel will over-balance weights 17 and 18 and the left hand end of the lever will be tilted downward to a definite angle with the horizontal closing the contacts 14 and 15 which will be maintained closed by the weight of the fly-wheel so long as it is in this position and, as disclosed above, a definite time interval after the electromagnet 20 is again energized. In case the electromagnet 20 is deenergized after the fiywheel has begun its travel but before it has passed the fulcrum of the lever, the fiywheel will be pushed back to the position shown inFig. 1, the contacts 14 and 15 remaining closed.

The time taken by the device in opening the contacts 14 and 15 may be varied by adjusting the contact 15 so as to vary the .angle of inclination of the lever 11 when in the closed circuit position, or by varying the effective length of the track by ad.- justing the position of stop 24.

It will be understood that although I have shown an electromagnet for governing the means for holding the fly-wheel in the circuit-closing position so as to release the fly wheel to cause the same to roll along the track and operate. a switch contact after a definite interval of time, and for governing the return movement of the fiy-wheel to the circuit closing position, it will be obvious to those skilled in the art that other operating means may be provided in accordance with the conditions imposed by the use to. which my invention is put.

It will also be obvious that my invention may be used to introduce a definite time interval in the closing of switch contacts instead of in opening the contacts.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof,

but I desire to have it understood that the the horizontal, a rotatable element having an axle of relatively small diameter adapted to roll on said support, circuit controlling means arranged to be operated upon the tilting of said support, means for holding the element in one position against its bias to roll downward along the support, and means for releasing the element to permit the same to roll past the pivot point of the support to tilt the same so as to give a time interval in the control of the electric circuit measured by the time taken by the element in rolling on the support from the said one position past the pivot point of the support.

2. A time element device for controlling electric circuits comprising a pivotally mounted support normally inclined from the horizontal and adapted to tilt to a position of greater inclination, a rotatable ele-' ment having an axle of relatively small diameter adapted to roll on said support, circuit controlling means arranged to be operated upon the tilting of said support, means for moving theelement to one position on said support and for holding it in this position, and means for disengaging the holding means to permit the element to roll past the pivot point of said support so as to tilt the same after a time interval measured by the time taken by the element in rolling on the support from said one position past thepivot point of the support.

s 3; A time element device for controlling electric circuits comprising a pivotally mounted tWo rail track arranged to be tilted from an inclined position to another position of greater inclination, a rotatable disc having an axle of relatively small diameter extending from each side thereof and adapted to support the disc between the rails of said track, circuit controlling means arranged to be operated upon the tilting of said track, means biased into engagement With said disc to move the same to one position on said track and hold the same therein, and electro-responsive means for disengaging said biasing means to permit said disc to roll past the pivotal support of said track so as to tilt the same after a time interval measured by the time taken by the disc in rolling on the track from said one position past the pivotal support of the track.

In Witness whereof, I have hereunto set ll my hand this 19th day of November, 1920 EUGENE PONS. 

